M2M (Machine to Machine) communication technology has come into the spotlight with the advent of ubiquitous era. M2M communication technologies have been intensively researched in many Standard Development Organizations (SDOs) such as TIA, ATIS, ETSI, etc. Communication between an M2M server part and an M2M client or M2M device (hereinafter referred to as M2M device) is of important to the M2M technologies. Generally, since communication between a small number of M2M servers and a large number of M2M devices occurs, communication overload may occur in the network between two entities. Since communication overload occurs and M2M devices are mainly used as battery-based communication devices, technologies for allowing the M2M devices to stay in a power-saving mode or a sleep mode for a longer time so as to increase a battery lifetime as well as to reduce power consumption are of important to M2M communication environments.
Communication frequently generated between the M2M server and the M2M server may periodically read values of sensors contained in the M2M device and then report the read values to the M2M server. In this case, it should be noted that all M2M applications do not require the measurement or report time as time critical information. Although a little time error occurs in a certain M2M application, the time error may not cause no problem to the M2M application, or may cause serious problems to the M2M application.
As a result, there is a need to develop a technology for reducing the amount of power consumed for the M2M device by optimizing a periodic report of the same resources in consideration of a parameter such as a time error, and at the same time reducing the amount of communication information between the M2M device and the M2M server.